No wrist raise - no heart rate

My apple watch suddenly stopped waking on wrist raise. I posted about two weeks ago but didn't get any real advice so I was hoping if I try again...

It began suddenly in about early October. First let me say it's an older watch that I bought certified refurbished, a series 3 and it's been working great! Very happy. Around the beginning of October, I noticed that when I put my watch on the charger the green circle arrow thing didn't show up on the face. I thought it wasn't charging and thought it was my charger as I haven't had the best luck with chargers. I tried my son's charger with the same effect. I finally decided to check my phone and saw that it was indeed charging and both charges were working properly. So when it charges there is no way to know when its placed on the charger.

Then next day or maybe the day after that I noticed that my watch wasn't waking on wrist raise. Of course, I went online first to see why this might be. I did all the obvious things. The first thing I saw was the theater mode - though I'd never heard of it I figured out what it was and checked it and discovered that theater mode was NOT THE PROBLEM! I mentioned I posted previously and in the post also said that theater mode was definitely not on, however, the only real responses I got suggested that it must be theater mode. I didn't really get anything else.

With theater mode absolutely off I made sure that wrist raise is checked and that nothing was changed as far as wrist placement. Every suggestion no matter how ridiculous I thought it was I tried it. I even went as far as erasing and setting up my watch from scratch as though it were brand new (to me) and there was no change.

During this time I started checking apps, kind of on a whim to see what worked and what didn't. It seemed everything was so I stopped opening and closing apps then cleared them all - having not opened and checked every app, not that I have that many, I'm old! On a whim, though I decided to check my heart rate app and it did NOT work. The little heart went round and round but no reading.

Then came an update and I thought OK, here we go!! This will fix it! After the update and restart, I put it on, and for about 5 minutes it actually worked - the wrist raise, heart rate, everything! Yay!! Then 5 minutes later they both stopped working again. Like before, everything else is working normally.

The only other thing that has been weird is that my watch will vibrate as though there is something...a text, a notification of some kind but when I check there is nothing. I will check my phone to see if there is any notification but there's nothing there. It has also occasionally toggled from silent to sound on or vice versa without me doing it OR without me going into the setting on my phone. I always make sure its on silent when I am teaching and I can feel when I get a notification but sometimes an hour or two into the morning I will suddenly start to get "ding" from my watch.

If anyone has read through the entire post (sorry I know its long) perhaps there is someone out there in the apple orchard who knows something?!?! I mean it still works even though it thinks I'm dead. I would like to have a heart rate reading. It would be convenient to see the time or notification when I raise my wrist rather than having to push the button --wow how lazy do I sound? Regardless. It is supposed to work in a certain way and now it doesn't so I am hoping I can do something to make it work correctly.

Thanks